The dispute over the cross-border Line 5 pipeline is entirely for Michigan to deal with, the state’s attorney general argues in a legal brief released Wednesday that flatly rejects Canada’s depiction of a foreign policy matter that Ottawa and the White House must resolve.

In a sternly-worded 21-page legal filing, Attorney General Dana Nessel excoriates the arguments of the pipeline’s owner, Calgary-based Enbridge Inc., as “meritless” and “baseless,” and waves away the submissions of the federal Liberal government, neighbouring states, and various industry stakeholders as little more than policy-based window-dressing, The Canadian Press reports.

Enbridge is trying to convince Michigan court Judge Janet Neff that the case needs to be heard by a federal judge because it raises “substantial federal questions” about Gov. Gretchen Whitmer’s effort to shut down the line for fear of an environmental disaster in the Great Lakes. Nessel disagrees.

“This case is a state law action through and through,” her brief begins. 

Michigan is “invoking powers that are unique to a state sovereign,” it says, and asserting claims under Michigan laws “over a strip of land that is owned by the state, located within the state, and held in trust by the state for the public benefit of its people.”

The dispute first erupted in November when Whitmer—citing the risk of a catastrophe in the Straits of Mackinac, the waterway where Line 5 traverses the Great Lakes—revoked the easement that had allowed the line to operate since 1953 and triggered a six-month deadline for Enbridge to close it down.

Enbridge insists the pipeline is safe and has already received the state’s approval for a $500-million effort to dig a tunnel beneath the straits that would house the line’s twin pipes and protect them from anchor strikes. The company has made it clear it has no intention of shutting down the pipeline voluntarily.

Advocates, including Natural Resources Minister Seamus O’Regan, say Line 5 delivers more than half the propane and home heating oil consumed in Michigan, and is a vital source of energy for Ohio and Pennsylvania as well, to say nothing of Ontario and Quebec.

Shutting it down would be an environmental disaster in its own right, they argue, resulting in gasoline shortages, price spikes, and some 800 additional oil-laden rail cars and 2,000 tanker trucks per day on railways and highways throughout Central Canada and the U.S. Midwest.

In a court filing of its own, known as an amicus brief, the federal government tried to up the ante, warning of damage to the relationship between Canada and the U.S. and the risk of undermining the future credibility of American foreign policy decisions.

The court should instead set aside the case and give the two countries a chance to negotiate a settlement under the terms of a 1977 treaty that specifically governs pipelines that cross the border, Canada argued.

Nonsense, Nessel countered. “The Canadian government’s suggestion that this court should hold this matter in abeyance pending dispute resolution under the treaty is without legal basis,” she wrote, noting that no such negotiations are currently under way.

“There is no reason for this court to delay or defer its determination of the issue now before it.”

Canada’s amicus brief, as well as three others from neighbouring states, as well as chambers of commerce in both countries, “primarily present policy arguments in favour of the continued operation of Line 5, based on economic considerations,” the filing says. “Such arguments about policy and the merits of Enbridge’s defences have no bearing on the legal issue now before the court: whether removal jurisdiction exists.”

Enbridge and state officials have been taking part in court-ordered mediation talks for the last several weeks, and an update that was filed in court last month indicated those talks would continue.

Canada’s brief leaned extensively on the close ties between the two countries, noting that they have successfully negotiated a bilateral agreement for protecting the Great Lakes, as well as the original NAFTA and its recent successor, the U.S.-Mexico-Canada Agreement.

Not everyone in Canada, however, opposes Whitmer’s efforts. A number of Indigenous groups in Ontario support a shutdown, as does Green party Leader Annamie Paul.

Paul has said Michiganders haven’t forgotten an Enbridge spill in 2010 that dumped more than 3.3 million litres of diluted bitumen into the Kalamazoo River, fouling more than 40 kilometres of shoreline. Enbridge walked away from that disastrous episode with a “wrist slap”.

This report by The Canadian Press was first published June 2, 2021.